Moderate alcohol intake has been shown to reduce coronary heart disease in numerous epidemiological studies. We propose that moderate ethanol consumption causes cardioprotection by increasing epsilonPKC protein expression in cardiac myocytes. To test this hypothesis, we will use multiple approaches to examine resistance of ischemia-reperfusion injury in hearts receiving ethanol in drinking water for at least 12 weeks. In addition, we will investigate the requirement for epsilonPKC function in ethanol-mediated cardioprotection using techniques routinely available in our laboratory with the following specific aims: Aim A: Examine epsilonPKC enzyme activity and subcellular localization in hearts from ethanol-fed mice and age-matched controls. We plan to identify ethanol-induced changes in epsilonPKC kinase function and distribution among subcellular compartments in adult cardiac myocytes and in left ventricular tissue from ethanol-fed mice and age-matched controls using immunofluorescence staining, confocal microscopy, immunoprecipitation, and western blotting techniques. Aim B: Determine whether acute isozyme-selective inhibition of epsilonPKC function blocks sustained ethanol-mediated cardioprotection. We will examine the effects of peptide modulators of PKC isozyme translocation and function introduced acutely into cultured adult cardiac myocytes or intact hearts on chronic ethanol-induced resistance to ischemia-reperfusion injury and PKC interactions with other signaling proteins. Aim C: Investigate the effects of moderate alcohol consumption on cardiac function and resistance to ischemia-reperfusion injury in epsilonPKC knockout mice. We will use adult cardiac myocytes and intact hearts to determine whether cardioprotection develops in epsilonPKC knockout mice in response to ethanol feeding and whether ethanol-mediated regulation of related signaling pathways is altered by the absence of epsilonPKC. One overall goal of this research is to understand the cellular mechanisms of cardioprotection mediated by chronic moderate alcohol consumption. A second goal is to identify therapeutic targets for sustained protection against coronary heart disease that do not require ethanol ingestion because of concerns regarding alcohol abuse and potential adverse effects on other organ systems in humans.